Originally posted by finnegan
Matter which moves at the speed of light becomes energy
no.. mass and energy are equivalent aspects of the same physical thing such as electric and magnetic fields are just experiences from a fundamental electro magnetic field.. (only depending on your frame of reference what you will see)
about 2/3 of the observable rest mass of a proton is just internal binding energy, and thereby the largest part of our own experiencable mass (some dozend kg)
m = the mass you would have if the energy was converted to mass(comes to rest) = E/c^2
no.. it is not the rest mass if you plug in the total energy..
as i already wrote:
E_0 = m_0 c^2
but E = m c^2
so this m is called apparent or relativistic mass and m_0 is the rest mass
and again a photon neither has E_0 nor m_0
E = energy of the photon, which could be anything along a spectrum, from your example E = 4 x 10^-19 kg (m/s)^2
so the mass of this photon would be 4.45 x 10^-36 kg if it came to rest
no.. this is the relativistic mass the photon allways has.. it has not to be "converted" or "halted" to get massive it just has the property of an apparent mass
(and a momentum you can easy see on solar sails *g*)
but i have to admit that photons (and all other energy distributions) also can create really massive particles
for example if you hit an atomic nucleous with a gamma ray over 1022 keV the photon creates an electron and a positron cite
The energy of the bullet can be determined according to its mass at rest, just multiply it by c^2
no
the total energy of a bullet (and all other particles) is just
E = sqrt( m_0^2 c^4 + p^2 c^2)
where p is the momentum the observer sees
[edit on 11-4-2008 by puerk]
[edit on 11-4-2008 by puerk]
